Gaskets are often used to seal mating mechanical components. One common application involves gasket placement between the engine block and cylinder head of an internal combustion engine. Cylinder head gaskets typically extend around cylinder bores to provide combustion seals, maintaining the high temperature gases of combustion within the cylinder bores. Simultaneously, the gaskets also seal fluid flow openings such as coolant and oil openings to prevent undesirable fluid mixing.
Fluids passing through the openings of a cylinder head gasket may be at high pressures and elevated temperatures. Therefore, gasket modifications are generally required to adequately seal the fluid openings. It is known to form an aperture in a main gasket body of the gasket to receive a separate sealing member.
Often the sealing member is secured to the main gasket body using an adhesive applied between the sealing member and the main gasket body, thereby permitting limited handling of the gasket to position it between the mating components. There are a number of disadvantages to using an adhesive. In particular, the gasket body and sealing member have limited cross-sectional areas. Thus, there is a relatively limited area of contact available for the adhesive. Additionally, the very nature of the gasket body, often formed from graphite having a low coefficient of friction, disfavors bonding between an adhesive and the gasket body. Yet, if an adhesive is adequately bonded to the gasket body, even limited handling often results in the flaking away of the portion of the gasket body in contact with the adhesive.
In view of such disadvantages, it is known to secure a fluid sealing member received within an aperture of a gasket body using a separate mechanical fastener. Such a fastener is secured to the sealing member and to the main gasket body adjacent the aperture to be sealed. However, through the use of a separate mechanical fastener, a portion of the clamping force from the bolted connection of the mechanical components is required to secure the fastener to the gasket body. Thus, this portion of the clamping force is not available to adequately compress the sealing member and prevent fluid leakage. The problem is further complicated when the aperture and received sealing member are positioned away from a bolted connection since the mechanical fastener reduces the already limited available clamping force.